Articles such as medical instruments should be sterilized before use. There are many methods of sterilization, including heat and chemical methods. Heat sterilization is normally done using steam. Some equipment cannot withstand either the heat or the moisture from steam treatment. As a result, chemical sterilization is now commonly used.
Chemical sterilization uses a sterilizing fluid such as hydrogen peroxide, ethylene oxide, chlorine dioxide, peracetic acid, or a combination thereof. A plasma may be induced to enhance the sterilization process. Although chemical sterilization is normally highly effective, it may not be as effective with medical devices containing long, narrow tubes, or lumens. Sterilization of these long lumens requires that the sterilizing agent penetrate the entire length of the long narrow tube. It is difficult for the sterilizing agent to completely penetrate these long narrow tubes. In order to enhance the penetration of the sterilizing agent down the entire length of the lumen, several forms of apparatus have been developed to flow sterilizing agent through the length of the lumen, thus enhancing the effectiveness of the sterilizing treatment.
For example, U.S. Pat. Nos. 4,410,492 and 4,337,223 describe a sterilization method in which the lumen is placed in a socket connected to a valve and a recirculating pump. The sterilizing gas is recirculated from the sterilization chamber through the lumen of the instrument. Although the method is effective at sterilizing the lumen, sterilization of endoscopes requires 2-3 hours using ethylene oxide as the sterilizing gas.
A method which delivers sterilizing agent down long, narrow lumens is described in U.S. Pat. No. 5,580,530. The lumen is inserted into an adaptor connected to a vessel containing hydrogen peroxide called the booster. The lumen, adaptor, and booster are all placed in the sterilization chamber. When the sterilization chamber is evacuated during the sterilization procedure, the hydrogen peroxide in the booster vaporizes and passes through the lumen, thereby sterilizing the interior of the lumen.
During use of the various sterilization methods, the lumen is held by a connecting device, a socket in the case of U.S. Pat. Nos. 4,410,492 and 4,337,223 or a truncated cone adaptor when using the method of U.S. Pat. No. 5,580,530. In all cases, there are areas of contact between the device and the lumen where the lumen attaches to the connecting device. It is difficult for the sterilizing agent to penetrate into these contact areas. There is a need for a method of enhancing the penetration of sterilizing gas into these contact areas more effectively to allay any potential concerns about incomplete sterilization.